1. Field of the Invention
This invention relates to a hand-held primer assembly for introducing starting fuel into the intake system of an internal combustion engine.
2. Description of the Prior Art
It is well known to use a flexible bulb with an inlet check valve and an outlet check valve to prime an internal combustion engine by manually squeezing the bulb to pump fuel into the engine and to suck fuel into the bulb as it is manually released. Because of the outlet check valve, the downstream pressure can become very high. Some new engines, which are fuel injected, include a vapor separator and float assembly, including a needle valve which is very light and relatively delicate. In fact, unduly high fuel pressure between the bulb and the float assembly could damage the needle valve.
In order to overcome such high pressure in the past, to prevent flooding of the engine, separate return systems have been combined with the flexible bulb, as disclosed in U.S. Pat. No. 3,233,652 to Phillips.
However, there remains a need for a system to relieve such high back pressure without the need of a separate return to prevent overcharging of the engine.